Short Message Service (SMS) is an inherent capability of most digital wireless telecommunications systems. The radio technologies associated with each of the digital wireless telecommunications system's are technically incompatible at the radio signal layer, but most are compatible at the intersystem SS7 transport layer. Currently, the differing RF technologies, e.g., time division multiple access (TDMA), code division multiple access (CDMA), and global system for mobile telecommunications (GSM), have at least partial technical compatibility over the IS41 industry standard that is currently carried over the telephone industry's SS7 inter-networking system. The partial compatibility of these RF technologies is possible because the basic transport format is specified in the IS41 standard; however, many of the messaging details are implementation specific.
Even though it is possible for current short message service center platforms (SMSC) to support all of these multiple protocols, typically, an installed SMSC only supports the protocol of the cellular telecommunication system into which it is installed. For example, if the SMSC is installed into an IS136 type TDMA system, the SMSC supports only the TDMA protocol. Similarly, if the SMSC is installed into a GSM system, then the SMSC supports only the GSM protocol. In other words, although most current SMSC's can interface with any of the currently popular digital cellular systems, the SMSC's do so on an individual basis, not all simultaneously.
For example, in one network, the nodes communicate using different data formatting standards, such as integrated services digital network (ISDN) and the Japanese X.50 standard. Each of the nodes is connected to a format converter. The format converter acts as a bidirectional converter for converting between two data formats and thus allows communication between the two nodes.
The format converter reformats the data formatted in the X.50 standard into the ISDN format. The format converter accomplishes the conversion by storing the incoming X.50 data in an aligned data RAM with offsets, to provide an appropriate alignment among the frames of the data. Then, a format conversion module reformats the data into the ISDN format one byte at a time.
In another network, a subscriber in an electronic messaging network can access messages in a variety of formats. A subscriber may receive messages through a variety of types of equipment, such as a voice mail system, an e-mail system, a facsimile machine and a telephone, all connected to a wireline network. The subscriber may access these messages through a pager, a cellular telephone, or a personal digital assistant, each connected to a different wireless network. The subscriber selects the wireline or wireless network and media format to be used for delivering messages or notifying a subscriber that a message has been received.
For example, the subscriber may elect to have notification of a voice mail or facsimile receipt directed to the personal digital assistant (PDA) in the form of an e-mail message. In accordance with the method of the network, the subscriber's selection is implemented through the personal intercommunications inter-networking system, which performs the appropriate data conversion from one protocol to another and delivers the e-mail message.
In yet another network, an intelligent signaling transfer point (ISTP) is included in a telephone network with a database for storing call processing control information. Calls from one station on the network to another are either passed through or intercepted at the ISTP and screened in accordance with criteria stored in the database, such as time of day, a certain originating area or caller, or a specified call count value.
In still another network, a data collection device is provided for use with any one of the following: TDMA; CDMA; frequency division multiple access (FDMA); GSM; and personal access communications systems (PACS) technologies. But, the data collection device does not use multiple such technologies in a single system.
Thus, there is a need for a system in which a central location can communicate with several remote stations, which use different digital cellular or personal communications system (PCS) formats. The systems and methods discussed above only teach conversion between two specific formats.